Visual aid



FIG. 1 is a top view of a visual aid showing my new design;

FIG. 2 is a bottom view of the device.

FIG. 3 is a right side view of the device.

FIG. 4 is a left side view of the device.

FIG. 5 is a back view of the device.

FIG. 6 is a front side view of the device; and,

FIG. 7 is an isometric view of the device. 

The ornamental design for visual aid, as shown and described. 